[64-bit] Android Studio: /dev/kvm device permission denied

When I try to run my Android app on an emulator I get this error:

/dev/kvm permission denied.

I checked the permissions and added the user I am currently logged in with to the kvm group. What is wrong?

Just one slight improvement on Jerrin's answer on fixing this error with Ubuntu 18.04 by utilizing $USER variable available in the bash terminal. So you could use the following commands two commands:

sudo apt install qemu-kvm

Add the current user to the kvm group

sudo adduser $USER kvm

Also if you are still having issues, one other problem for me was the way in which I installed Ubuntu. I made the mistake of checking the box during installation for installing 3rd party software which did not play nice with my nvidia graphics card for development. So I reinstalled Ubuntu with this third party software unchecked.

Then after installation, open up Software & Updates and go to the Additional Drivers tab. Select the most up to date proprietary drivers that have also been tested and apply changes. Should restart the machine for the changes to take affect.

Type in terminal:

sudo apt install qemu-kvm -y
sudo chown $USER /dev/kvm

In order to make a virtual device in Linux - I have to follow this three command and it helps me to avoid trouble for building avd devices - the process are -

sudo apt install qemu-kvm
sudo adduser $USER kvm
sudo chown $USER /dev/kvm 

so, now you are good to go, restart android studio and start building application with emulator.

Open Terminal and log as admin

sudo su

Go to the dev folder

cd /dev/

Change the kvm mode

chmod 777 -R kvm

I got this error after updating my ubuntu to 18.04.1. I just download new system image for emulator or you can say that download new emulator and it is worked for me.

Have you also tried following, it should work:

sudo chown <username> /dev/kvm
sudo chmod o+x /dev/kvm

What finally fixed it for me on Ubuntu 18.04 was:

sudo apt install qemu-kvm
sudo adduser $USER kvm
sudo chown $USER /dev/kvm

sudo setfacl -m u:$USER:rwx /dev/kvm

Worked for me.

I was in a similar situation with the same error of permissions on /dev/kvm I had done the necessary installations but not added the user to the kvm group All I had to do was

sudo adduser <Replace with username> kvm

and ofcourse DON'T forget to restart your Ubuntu instance.

Running the below command in Ubuntu 18.04 worked for me sudo chown -R /dev/kvm

Try this, it worked for me:

1. sudo apt install qemu-kvm

2. sudo chown -R <username>:<username> /dev/kvm

I countered the same problem and to solve this issue just type the following commands in terminal for Linux clients

   sudo apt-get install qemu-kvm

    // type your password

   sudo chmod 777 -R /dev/kvm

and after that try running simulator it'll work

As mentioned in the comments, starting with Ubuntu 18.04 and Linux Mint Tara you need to first sudo apt install qemu-kvm.

To check the ownership of /dev/kvm use

ls -al /dev/kvm

The user was root, the group kvm. To check which users are in the kvm group, use

grep kvm /etc/group

This returned

kvm:x:some_number:

on my system: as there is nothing rightwards of the final :, there are no users in the kvm group.

To add your user to the kvm group, you could use

sudo adduser $USER kvm

which adds the user to the group, and check once again with grep kvm /etc/group.

As mentioned by @marcolz, the command newgrp kvm should change the group membership live for you. If that did not work, @Knossos mentioned that you might want to log out and back in (or restart), for the permissions to take effect. Or do as @nmirceac mentioned and re-login in the same shell via su - $USER.

This is how I got it to work in Ubuntu 18.04

sudo apt install qemu-kvm

Add your user to kvm group using:

sudo adduser <Replace with username> kvm

If still showing permission denied:

sudo chown <Replace with username> /dev/kvm

Try it.

Step 1: (Install qemu-kvm)

sudo apt install qemu-kvm

Step 2: (Add your user to kvm group using)

sudo adduser username kvm

Step 3: (If still showing permission denied)

sudo chown username /dev/kvm

Final step:

ls -al /dev/kvm

If you open your ide with sudo. You are not going to have this problem.

I am using linux debian, and i am facing the same way. In my AVD showing me a message "/dev/kvm permission denied" and i tried to find the solution, then what i do to solve it is, in terminal type this :

sudo chmod -R 777 /dev/kvm

it will grant an access for folder /dev/kvm,then check again on your AVD , the error message will disappear, hope it will help.

Here is a simple solution

open the terminal and run the following commands

sudo groupadd -r kvm

sudo gedit /lib/udev/rules.d/60-qemu-system-common.rules

Add the following line to the opened file and save it

KERNEL=="kvm", GROUP="kvm", MODE="0660"

Finally run:

sudo usermod -a -G kvm <your_username>

Reboot your PC and Done!

This is because /dev/kvm is not accessible. To make is accessible from android studio run the below command

sudo chmod 777 -R /dev/kvm

It will ask for your password. After that restart Android Studio.

KVM is required to rum emulator. If you have not install it yet then install it

sudo apt install qemu-kvm

I am using ubuntu 18.04. I was facing the same problem. I run this piece of command in terminal and problem is resolved.

sudo chown $USER /dev/kvm

the above command is for all the user present in your system.

If you want to give access to only a specific user then run this command

sudo chown UserNameHere /dev/kvm

This Worked For Me on Linux (x18) ☑ Hope It Will Work For You Aswell

sudo chown hp /dev/kvm

There's absolutely no need to install qemu-kvm (and all its dependencies) if you only want to run the Android Studio Emulator.

The only thing you have to do is to give your user (i.e. the one you are logged in with) the right to access the /dev/kvm-device.

This is done in three simple steps.

Create the kvm-group

groupadd -r kvm

The option -r creates a system group, i.e. with a GID <= 999 (see /etc/login.defs => SYS_GID_MAX)

Change permissions on /dev/kvm. This could be done as part of the qemu-kvm-installation, because one of the dependencies is installing qemu-system-common (on current Ubuntu systems, package name may vary), which in turn installs the file /lib/udev/rules.d/60-qemu-system-common.rules containing the following:

KERNEL=="kvm", GROUP="kvm", MODE="0660"

So if you are just create a file /etc/udev/rules.d/60-qemu-permissions.rules containing the above line, you are done with the first step.

Add your username to the group by executing

usermod -a -G kvm <your_username> - the -a is important for adding your user to the kvm-group. Without that you will overwrite the group-settings for your user to only belonging to "kvm"...

That's it.

For the new udev rule and group setting to take effect it's easiest to reboot and login again.

You can also execute

udevadm control --reload-rules && udevadm trigger

for reloading the rules but you still have to logout and login again with regard to the new group.

Under Ubuntu, the permissions of /dev/kvm usually look like this:

$ ls -l /dev/kvm
crw-rw---- 1 root kvm 10, 232 May 24 09:54 /dev/kvm

The user that runs the Android emulator (i.e. your user) needs to get access to this device.

Thus, there are basically 2 ways how to get access:

• Make sure that your user is part of the kvm group (requires a re-login of your user after the change)
• Widen the permissions of that device such that your user has access (requires a change to the udev daemon configuration)

Add User to KVM Group

Check if your user is already part of the kvm group, e.g.:

$ id 
uid=1000(juser) gid=1000(juser) groups=1000(juser),10(wheel)

If it isn't then add it with e.g.:

$ sudo usermod --append --groups kvm juser

After that change you have to logout and login again to make the group change effective (check again with id).

Widen Permissions

Alternatively, you can just can widen the permissions of the /dev/kvm device.

Example:

echo 'KERNEL=="kvm", GROUP="kvm", MODE="0666", OPTIONS+="static_node=kvm"' \
    | sudo tee /etc/udev/rules.d/99-kvm4all.rules
sudo udevadm control --reload-rules
sudo udevadm trigger --name-match=kvm

FWIW, this is the default on other distributions such as Fedora and CentOS.

Check the effectiveness of the above commands with another ls. You should see output similar to:

$ ls -l /dev/kvm
crw-rw-rw-. 1 root kvm 10, 232 2020-05-16 09:19 /dev/kvm

Big advantage: You don't need to logout and login again for this change to be effective.

Non-Solutions

• calling chmod and chown directly on /dev/kvm - 1) these changes aren't persistent over reboots and 2) since /dev/kvm permissions are controlled by the udev daemon, it can 'fix' its permissions at any time, e.g. after each emulator run
• adding executable permissions to /dev/kvm - your emulator just requires read and write permissions
• changing permissions recursively on /dev/kvm - I don't know what's up with that - looks like cargo cult
• installing extra packages like qemu - you already have your emulator installed - you just need to get access to the /dev/kvm device

Although KVM is a module built into the Linux kernel itself, it doesn't mean that all the necessary packages are included in your Ubuntu/Linux install by default. You'll need a few to get started, and they can be installed with this command in the terminal:

& sudo apt install qemu-kvm libvirt-clients libvirt-daemon-system bridge-utils virt-manager    

Configure the network bridge

In order for your virtual machines to access your network interface and be assigned their own IP addresses, we need to configure bridged networking on our system.

First, run the following Linux command in order to find out what name your network interface has been assigned. Knowing this will allow us to do additional configuration later.

$ ip a     

In my case, the network interface is called enp2s0. Yours will likely be very similarly named.

In order to tell Ubuntu that we want our connection to be bridged, we'll need to edit the network interfaces configuration file. Doing this won't negatively impact your connection at all. It'll just allow that connection to be shared with the VMs.

Use code (Visual Studio Code) or your favorite text editor to open the following file:

$ code /etc/network/interfaces     

When you first open this file, it may be empty or contain just a couple of lines. Your bridge interface is called br0, so add the following line for the interface to come up by default:

auto br0    

Below this line, add the following line for your current network interface (the one who's named you determined earlier).

iface enp2s0 inet manual

Next, you can add the bridge information. These lines tell Ubuntu that your bridge will use DHCP for automatic IP address assignment, and your bridge will manage your current interface.

iface br0 inet dhcp
      bridge_ports enp2s0

This is how your file should look once all the changes have been applied (if you also have a couple of lines that were already there, it's fine to have them too):

Save your changes and exit the file.

Add your user to the groups

In order to manage your virtual machine(s) without root privileges, your user will need to belong to two user groups. Run the following commands to add your user to the appropriate groups (replacing user1 with the name of your user):

$ sudo adduser user1 libvirt
$ sudo adduser user1 libvirt-qemu
$ sudo adduser user1 kvm

When you're done, you should restart your system to ensure that all of the changes done to your user and network configuration have a chance to take effect.

sudo chown $USER /dev/kvm

Simply running that one command worked for me here in September 2019 running:

Description: Ubuntu 18.04.3

LTS Release: 18.04

Codename: bionic

1. I tried sudo setfacl -m u:UserName:rwx /dev/kvm . and it works .

2. In the android studio you need to change : tools> avd manager >(chose the pen to edit your device and change 'graphics' from automatic to software ) to avoid emulator drawable error

Provide appropriate permissions with this command

sudo chmod 777 -R /dev/kvm